Nation's Waters yield a Drugstore in U.S. Survey

Researchers at the USGS have tested for 95 chemicals in 139 streams in 30 states. Eighty per cent of the streams contained at least one and up to 38 of the chemicals. Chemical testing was extremely sensitive testing in parts per bilion.

They found traces of dozens of drugs, disinfectants, hormones, chemicals excreted by smokers, and other contaminants. This includes compounds used in birth control and hormone-replacement therapy. Levels were similar to those that other studies had linked to damage to fish and other aquatic wildlife.

Chemicals found south of the Twin Cities include caffeine, ticlosan - the active ingredient in antimicrobial soaps, cholesterol and coprostanol - two steroids, the disinfectant phenol, tri(2-chloroethyl) phosphate - a flame retardant, bisphenol A - used in making plastics, and three antibiotics used in hog feed.

The concern with antibiotics is that bacteria develop a resistance and diminish the effectiveness of human drugs. Natural and synthetic estrogen in treated wastewater affets the sexual development of fish.

Sewage treatment plants use natural bacteria to treat wastewater. the process removes 95% of many pollutants but has no effect on some compounds.

Federal food and drug officials said the USGS study could lead to changes in the drug approval process. The agency could require more drugs to undergo tests for hazards they might pose once they leave the body.